There has been of late interest in smoke or gas detectors which provide visual alarm indicators as well as audible alarm indications. For example, it has been recognized that hearing impaired individuals may not hear a normal fire or smoke alarm. This is especially the case when such individuals are sleeping.
It has been known to couple high intensity strobe lights to smoke detectors so as to provide a visual output. Known circuits for driving such strobe lights, such as xenon tubes, have suffered from both variations in flash rate and also unwanted heat dissipation in response to variations in applied AC electrical energy.
It would be desirable to be able to limit the extent of heat dissipated in such circuits, along with associated temperature increases, in spite of increases in applied AC line voltage. Additionally, it would be desirable to maintain a constant flashing rate in the presence of variable applied AC voltage and also to provide a uniform degree of illumination from the strobe light notwithstanding such voltage variations.